docs: Add labels for supported hardware

This gives us the ability to easily reference them in various other
parts (eg. release notes).

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>

docs/hardware-support/boards/raspberrypi4.rst

@@ -15,6 +15,12 @@ Raspberry Pi 4 Model B
 Overview
 ********
 
+.. note::
+
+   Even though this documentation targets Raspberry Pi 4, in Oniro, the same
+   image provides support for Raspberry Pi 3 as well. This means that the
+   following considerations and instructions apply to both types of hardware.
+
 Raspberry Pi 4 Model B is powered with Broadcom BCM2711, quad-core Cortex-A72
 (ARM v8) 64-bit SoC @ 1.5GHz. This product's key features include a
 high-performance 64-bit quad-core processor, dual-display support at

docs/hardware-support/virtual-boards/qemuarm-efi.rst

@@ -4,6 +4,8 @@
 
 .. include:: ../../definitions.rst
 
+.. _SupportedVBoardQemuARM:
+
 Qemu ARM 32bit
 ##############
 

docs/hardware-support/virtual-boards/qemuarm64-efi.rst

@@ -4,6 +4,8 @@
 
 .. include:: ../../definitions.rst
 
+.. _SupportedVBoardQemuARM64:
+
 Qemu ARM 64bit
 ##############
 

docs/hardware-support/virtual-boards/qemux86-64.rst

@@ -4,6 +4,8 @@
 
 .. include:: ../../definitions.rst
 
+.. _SupportedVBoardQemuX86-64:
+
 Qemu X86-64
 ###########
 

docs/hardware-support/virtual-boards/qemux86.rst

@@ -4,6 +4,8 @@
 
 .. include:: ../../definitions.rst
 
+.. _SupportedVBoardQemuX86:
+
 Qemu X86
 ########